1. Field of the Invention
The present invention relates to insulated walls, and in particular to such walls having outer layers of poured concrete and an inner insulating layer or layers of organic or inorganic rigid insulation board rigidly held therebetween.
2. Description of the Prior Art
It is well known in the construction industry to utilize metal or wooden forms to retain poured concrete during original hardening of the concrete.
It is also known in the construction industry to utilize a pair of opposed parallel outer slabs of concrete containing an inner layer of foamed insulation such as polyurethane to improve the insulation properties of poured walls. Such a structural combination is disclosed and claimed in U.S. Pat. No. 3,750,355.
It is known to pour concrete in forms with a sheet of polystyrene against one of the forms and after hardening moving that form to a new position and pouring second concrete face against the polystyrene and form in a second stage. This requires a two stage pour and extra labor to set part of the form twice. In addition, the contractor has his forms tied up for a longer period of time.